Sol Campbell in action for his new club Newcastle in a reserve match against Sunderland. Photograph: Craig Brough/Action Images

Sol Campbell says he still has the desire to play for England and claimed that, at 35, he can perform to the same level as when he was 30 years old.

Campbell joined Newcastle United in the summer as a free agent from Arsenal and made his first appearance for the club on Tuesday evening for the reserves in a 3-1 victory over Sunderland.

Asked if he is good enough to play for England, Campbell, who won the last of his 73 caps three years ago, said: "I think last season for sure. I have still got it. I still have the passion, the fire in my belly. I want to win. But you just can't do anything about it any more. So I am not going to fight. I am going to fight on the pitch for Newcastle and if it comes to the stage where someone says can you fight for England then I will fight for England. But I am not going to go on about it. It is just not worth it.

"I'm just going to concentrate on Newcastle and if anything happens at a later stage it happens. I have just got to get my football right and concentrate on moving Newcastle in the right direction and if anything happens in the future, it happens."

Campbell said he has never retired from international football and, after a successful spell at Arsenal in the second half of last season, hinted at disappointment that Fabio Capello did not recall him for the World Cup squad.

"I never mentioned that I was retiring, no. If people don't like you, people don't like you. It's as simple as that. But then maybe I should have retired and maybe he would have brought me out. Who knows?" Campbell said, referring to Capello's attempt to persuade Paul Scholes to play, and Jamie Carragher's brief return from international exile.

Campbell added: "It doesn't matter where you are at with your age, if you are fit and you are strong, and you are physically there and want it, then you have got the experience so I think there should be no problem really.

"Last season I worked really hard and I think I showed to all the people that if you work hard then you are there. If you get an opportunity, you get an opportunity, but it really comes down to the people behind the scenes and the manager. You can't do anything about it. I could have scored 10 goals in the first half of the season. It doesn't matter."

Campbell is now looking forward to the challenge of playing at St James' Park. He said: "With Newcastle there are 50,000 people watching and they want it to be a success, and that is what I am all about. I remember going to Portsmouth and people [asking] what going there is all about, and I came away with an FA Cup and a European campaign. That is what I am all about."